1) isolate the 2 layer stuff to a seaparate FAQ "how to get by with 2 layers if you can not do the right thing and use 4 layers". The mixing of 2 layer stuff in a noise list makes everyone believe that they can get by with 2 layers which is not true.

Erik,

how can you make such a statement after all the discussion we had over the last months??
A double sided printed circuit board being routed properly to get a solid ground plane can make you meet the CE compliance VERY WELL!!!

Not all people are living in the rich USA and can buy a four layer board everytime they want. There are many places in the world, where the cost of a four layer board is higher than the 3 months salary of an electronics engineer. And these people NEED URGENTLY a methode to make their applications to meet FCC rules or CE standards. And using a double sided PCB containing a solid ground plane, even if the solidity couldn't be fully implemented, IS a very helpful nethode to manage EMC issues!

You wrote:

The mixing of 2 layer stuff in a noise list makes everyone believe that they can get by with 2 layers which is not true.

And this statement is totally wrong!! Of course you can 'get by' with 2 layers in very many cases! Have a discussion with an EMC engineer...

Many people think, that a multilayer board is a panacea, which solves every problem. But it isn't! If you have many through hole chips on your board, then ground planes and Vcc planes can be heavily interrupted, resulting in a board which can easily violate CE standards or FCC rules!
And how to manage things, when using ADCs and DACs on the same board? Here just using a multilayer board can make your apllication totally fail. Here, you must think again about how to route ground planes very properly, how to split them in the right way, how to use common mode filtering between the individual planes, how to connect enclosure and connectors to a suited ground...

A person who has learned to design a double sided PCB containing a solid ground plane is more likely to design a perfect mixed analog / digital board, than a person who all time take this four layer board, never thinking about how to route ground properly...


Please stop making statements, telling that a double sided PCB isn't suited to meet CE standards and FCC rules, because these statements are just wrong!


Kai